Question

The reaction $2A+B_2\to 2AB$ is an elementary reaction. For a certain quantity of reactants, if the volume of the reaction vessel is reduced by a factor of 3, the rate of the reaction increases by a factor of (Round off to the Nearest Integer)

Answer 1

For elementary reaction,

$\text{Rate of reaction}=K\left[A{]}^2\right[B_2]$

$\text{Initial rate}=K{\left(\frac{n_A}{v_o}\right)}^2\left(\frac{n_B}{v_o}\right)$
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$\text{Final rate}=K{\left(\frac{n_A}{v_o/3}\right)}^2\left(\frac{n_B}{v_o/3}\right)=27K\left(\frac{n_A}{v_o}\right)\left(\frac{n_B}{v_o}\right)$

$\text{Final rate}=27\times \text{Initial rate}$
So, the correct answer is 27